This module allow to generate files using template. Each template files
is split into three parts: an header, a body and a footer. We target at
changing the body part. If target file already exists, we load the header
and the footer from it. We merge the three parts and repalce the target
files.

template_of_string_list ~ctxt ~template fn cmt lst Split a the
list lst of into an header, a body and a footer, using comment
cmt to determine each part. Set ~template if this is an
embedded template (i.e. not a file loaded from disk). See
OASISFileTemplate.template_make for other options.